spring boot——集成JPA——入门示例002

pom文件：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.1.7.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.ch</groupId>
    <artifactId>ch6_1</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>ch6_1</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>11</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- 添加MySQL依赖 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.45</version>
            <!-- MySQL8.x时，请使用8.x的连接器 -->
        </dependency>
        
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

application.properties如下：

server.servlet.context-path=/ch6_1
###
##数据源信息配置
###
#数据库地址
spring.datasource.url=jdbc:mysql://localhost:3306/springbootjpa?characterEncoding=utf8
#数据库MySQL为8.x时，url为jdbc:mysql://localhost:3306/springbootjpa?useSSL=false&serverTimezone=Asia/Beijing&characterEncoding=utf-8
#数据库用户名
spring.datasource.username=root
#数据库密码
spring.datasource.password=root
#数据库驱动
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
#数据库MySQL为8.x时，驱动类为com.mysql.cj.jdbc.Driver
####
#JPA持久化配置
####
#指定数据库类型
spring.jpa.database=MYSQL
#指定是否在日志中显示SQL语句
spring.jpa.show-sql=true
#指定自动创建、更新数据库表等配置，update表示如果数据库中存在持久化类对应的表就不创建，不存在就创建对应的表
spring.jpa.hibernate.ddl-auto=update
#让控制器输出的JSON字符串格式更美观
spring.jackson.serialization.indent-output=true

整体如下：

MyUser

package com.ch.ch6_1.entity;
import java.io.Serializable;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
@Entity
@Table(name = "user_table")
/**
 * 如果没写表名，默认为类名的词组
 * （如MyUser类对应的表名为my_user）
 */
public class MyUser implements Serializable{
    private static final long serialVersionUID = 1L;
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private int id;//主键
    /**使用@Column注解，可以配置列相关属性（列名，长度等），
     * 可以省略，默认为属性名小写
     */
    private String uname;
    private String usex;
    private int age;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getUname() {
        return uname;
    }
    public void setUname(String uname) {
        this.uname = uname;
    }
    public String getUsex() {
        return usex;
    }
    public void setUsex(String usex) {
        this.usex = usex;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
}

UserRepository

package com.ch.ch6_1.repository;
import java.util.List;
import org.springframework.data.jpa.repository.JpaRepository;
import com.ch.ch6_1.entity.MyUser;
/**
 * 这里不需要使用@Repository注解数据访问层，
 * 因为Spring Boot自动配置了JpaRepository
 */
public interface UserRepository extends JpaRepository<MyUser, Integer>{
    public MyUser findByUname(String uname);
    public List<MyUser> findByUnameLike(String uname);
}

UserService

package com.ch.ch6_1.service;
import java.util.List;
import com.ch.ch6_1.entity.MyUser;
public interface UserService
{
    public void saveAll();
    public List<MyUser> findAll();
    public MyUser findByUname(String uname);
    public List<MyUser> findByUnameLike(String uname);
    public MyUser getOne(int id);
}

UserServiceImpl

package com.ch.ch6_1.service;
import java.util.ArrayList;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import com.ch.ch6_1.entity.MyUser;
import com.ch.ch6_1.repository.UserRepository;
@Service
@Transactional
public class UserServiceImpl implements UserService{
    @Autowired
    private UserRepository userRepository;//依赖注入数据访问层
    @Override
    public void saveAll() {
        MyUser mu1 = new MyUser();
        mu1.setUname("陈恒1");
        mu1.setUsex("男");
        mu1.setAge(88);
        MyUser mu2 = new MyUser();
        mu2.setUname("陈恒2");
        mu2.setUsex("女");
        mu2.setAge(18);
        MyUser mu3 = new MyUser();
        mu3.setUname("陈恒3");
        mu3.setUsex("男");
        mu3.setAge(99);
        List<MyUser> users = new ArrayList<MyUser>();
        users.add(mu1);
        users.add(mu2);
        users.add(mu3);
        //调用父接口中的方法saveAll
        userRepository.saveAll(users);
    }
    @Override
    public List<MyUser> findAll() {
        //调用父接口中的方法findAll
        return userRepository.findAll();
    }
    @Override
    public MyUser findByUname(String uname) {
        return userRepository.findByUname(uname);
    }
    @Override
    public List<MyUser> findByUnameLike(String uname) {
        return userRepository.findByUnameLike("%" + uname + "%");
    }
    @Override
    public MyUser getOne(int id) {
        //调用父接口中的方法getOne
        return userRepository.getOne(id);
    }

}

UserTestController

package com.ch.ch6_1.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import com.ch.ch6_1.service.UserService;
@Controller
public class UserTestController {
    @Autowired
    private UserService userService;
    @RequestMapping("/save")
    @ResponseBody
    public String save() {
        userService.saveAll();
        return "保存用户成功！";
    }
    @RequestMapping("/findByUname")
    public String findByUname(String uname, Model model) {
        model.addAttribute("title", "根据用户名查询一个用户");
        model.addAttribute("auser", userService.findByUname(uname));
        return "showAuser";
    }
    @RequestMapping("/getOne")
    public String getOne(int id, Model model) {
        model.addAttribute("title", "根据用户id查询一个用户");
        model.addAttribute("auser",userService.getOne(id));
        return "showAuser";
    }
    @RequestMapping("/findAll")
    public String findAll(Model model){
        model.addAttribute("title", "查询所有用户");
        model.addAttribute("allUsers",userService.findAll());
        return "showAll";
    }
    @RequestMapping("/findByUnameLike")
    public String findByUnameLike(String uname, Model model){
        model.addAttribute("title", "根据用户名模糊查询所有用户");
        model.addAttribute("allUsers",userService.findByUnameLike(uname));
        return "showAll";
    }
}

posted @ 2022-05-29 18:58 小白龙白龙马阅读(53) 评论(0) 收藏举报

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